1. Field of the Invention
The present invention relates to a photomask case, a transporting apparatus, and a transporting method; and, in particular, to a photomask case used when making a semiconductor, a liquid crystal display device, or the like in a photolithography process, and a transporting apparatus and method for transporting this photomask case.
2. Related Background Art
In a lithography process (process of forming a resist image of a mask pattern onto a substrate) for making a semiconductor device and the like, there is used a projection exposure apparatus (stepper or the like) for exposing, by way of a projection optical system, a reticle pattern as a photomask (hereinafter referred to as mask) onto a substrate (or a wafer or the like) coated with a photoresist.
There has been proposed an automatic transportation system which automatically transports this mask in a state accommodated in a photomask case (hereinafter referred to as mask case) successively through various processing apparatus such as a cleaning apparatus for the mask, a dust inspecting apparatus, a pellicle mounting apparatus, an exposure apparatus, and the like. According to this automatic transportation system, when a mask case is to be transported between various apparatus, the mask having completed its processing within a processing apparatus is accommodated in the mask case and is transported by a transporting section of this processing apparatus to a mask delivery site in the processing apparatus and is placed there.
The mask case placed at the delivery site of the processing apparatus is transported by an external transporting apparatus to a delivery site of another processing apparatus and is placed there. The mask case placed at the delivery site of this processing apparatus is adapted to be transported by a transporting section of the processing apparatus to a predetermined processing site.
When the mask case is transported between various processing apparatus, positional deviations at the time of delivering the mask case become problematic. Unless the transporting section of a processing apparatus places a mask case at the delivery site of this processing apparatus with a certain degree of accuracy, the external transporting apparatus cannot hold this mask case, so that an error will occur in the system, thereby making the subsequent processing impossible.
It is an object of the present invention to provide a mask case, transporting apparatus, and transporting method which can accurately achieve positioning when transporting the mask case. Namely, a predetermined part of the mask case is provided with a positioning depression into which a support pin projecting from an installation site is inserted, whereby accurate positioning is effected. If positioning depressions of the mask case are arranged such that their deepest portion is disposed on the outer side of the mask case than is a support member for supporting a mask, then it is possible to reduce the total height of a plurality of mask cases when they are stacked.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.